Apparatus for purifying liquid lubricants



April l, 1941. M ARMBYRUSTER v 2,236,769

APPARATUS Fon PuR-IFXING LIQUID LUBRIcANTs l Fileduan.' l14.'.v 1959 v PZH?, Vif?! UNITED-STATES PATENT OFI-ica i me Max Armbruster, Wiesbaden-Blebrich, Germany Application January 14, 1939, Serial No. 251,035

GermanyJanuary 13, 1938 Claims. (Cl. 209-215) then carried bythe lubricating liquid tothe vari- This invention relatesto an apparatus for purifying mechanically contaminated liquid lubricants such as oils, oil mixtures and oil emulsions by separating metallic and non-metallic impurities therefrom. The apparatus consists essentially of a, centrifuge for imparting a rotary movement to the lubricatim liquid to be cleaned or purified whereby the particles of impurities are thrown into settlement vchambers vwhich are under influence of magnetic fields of force -by which the magnetisable constituents in the impurities are attracted and retained and thereby separated.

'I'hisapparatus can be built into the sump of a power vehicle. It can also be connected directly in front of the oil pump of a lubricant circulating system if too great a pressure need not be overcome, and may also take the place of such a system if the centrifugal wheel is of suitable construction.

For retaining the finest particles of suspended matter a ne-meshed screen of suitable fine meshed fabric can be arranged after the apparatus, for example in the outlet opening leading therefrom. Y.

When the centrifugal apparatus is built into a power vehicle or the like it operates entirely automatically while the vehicle is travelling and ensures that only a lubricant which has been freed from all mechanical impurities is supplied to the places to be lubricated. It can be driven from any suitable part of the engine, for example from'the oil pump of a lubricant circulating system.

Hitherto for purifying or filtering lubricating liquids, such as oils, oil mixtures, oil emulsions and the like, only ne mesh screens, fabrics or metal plates superimposed at aesmall distance apart, so called gap or laminated filters, have been employed. These devices however were not satisfactory since, as has been found in practice, in the case of lters made of fabric, owing to the excess pressure produced by the deposit thereon, the impurities were forced through thefabric and also carried al small part of the ltering material along with them. Laminated lters and metallic screens have the disadvantage that they retain only the coarser metallic and other particles, while the finest particles, for example the particles of iron which have been rubbed from iron crankshafts and other shafts and bronze particles which have been rubbed by friction from bearings and the finest particles of moulding sand which become detached from castings, are allowed to pass through. Such particles are fuge which can be subdivided into compartments nated lubricating liquid is passed through a cen.

trifuge by which the impurities are thrown into the magnetic fields of force of the casing of the centrifuge.

The centrifuge may consist, for example, of one or of a plurality of superimposed rotary discs or blade wheels and a stationary casing having magnetic ribs disposed radially therein. It may also consist of a rotary casing which is subdivided into compartments by a plurality of fixed spaced partitions or ribs arranged inside the casing. In this latter instance the ribs may be in the form of curved blades amxed to the wall of the casing and projecting into the chamber containing the stationary partitions. of construction the outer wall of the casing or the ribs are Wholly or partly magnetic so as to attract and retain magnetisable metallic impurities. Further advantages of the new centrifuging apparatus having magnetic elds of force are that, as distinguished from the known filters, the openings and passages for the flow of the lubricating liquid may be relatively large so that there is no danger that they may quickly become choked. Also the outer chamber of the centriby ray-like walls having magnetic fields of force and the flow of liquid through it can be as large as desired, so that the deposit formed by the particles "of impurities attracted by the magnetic walls does not interfere with the flow and the centrifuging of the lubricating liquid. In those cases in which no or only a low lubricating pressure is necessary the apparatus can be constructed after the manner of a circulating pump, i. e.,

the rotary centrifugal blade wheel or wheels mounted therein can be constructed as conveyor wheels which draw up the lubricating liquid and force it in a clean condition to the places toA be lubricated. When a higher lubricant pressure is required, as incirculatory lubricating systems of,

for example, compressors and internal combus- In this form fixed to a rotary casing.

tion engines, the apparatus is connected in front of the usual oil pump as has been previously mentioned. The oil pump also can then conduct only purified lubricant to the places to be lubricated. In the case of engines having circulatory lubricating systems, the lubricant circulates continuously within a short time, so that the fine particles which have been rubbed off by wear or abrasion from crankshafts, bearings, toothed wheelspiston guides and so forth are taken up in the lubricant or oil. Consequently. the purifying apparatus which rotates continuously while the engine is running continuously separates the impurities which, in so far as they are magnetisable, are retained by the magnetic fields, so that only a lubricant which has been completely freed from all mechanical impurities can reach the places to be lubricated.

The invention therefore is particularly adapted for use with engines having circulatory lubricating systems.

In order that the invention may be readily understood and carried into effect a lubricant purifying or cleansing apparatus constructed in accordance with the invention is illustrated by way of example in the accompanying drawing, in which Figure 1 is a vertical section through the apparatus.

Figure 2 is a diagrammatic horizontal section on the line A-B of Figure 1 through the apparatus which has a stationary casing and two su perimposed centrifugal wheels arranged therein.

Figure 3 is a diagrammatic horizontal section through an apparatus having blade-like ribs Figure 4 is a vertical section through an apparatus having a stationary casing and only one centrifugal blade wheel which is driven from a shaft of the oil pump to which it directly supplies the purified lubricant, and

Figure 5 is a perspective view of a part of a centrifugal wheel constructed to act also as a conveyor wheel; blades are inclined slightly at an angle to the wheel. y

Referring to Figures l and 2 of the drawing, the reference a denotes the stationary casing of the apparatus. the side wall of which is pro. vided with inwardly directed radial ribs a1- and the bottom with an inlet a2 for the lubricant to l be cleaned. The ribs a1 are provided with magnetic fields of force and are therefore able to attract and retain magnetisable particles of the metallic impurities. The casing of the apparatus is subdivided into two superimposed compartments by means of a horizontal partition or inteimedlate bottom b. Each of these'compartments is fitted with a centrifugal wheel d and d1 respectively of suitable diameter having blades e and e1. Ihe wheels d and d1 are mounted on a shaft j of one of the toothed wheels of an oil pump. g, y1 which in the example illustrated is constructed as a gear pump. The cover a3 of the casing a is provided with apertures a4 for the outlet of the purified lubricant into the gear pump. Fine-mashed screens may be inserted in the apertures a4 for retaining any suspended matter. The reference h denotes arcuate ribs which are relatively staggered and are tted on the underside of the intermediate bottom b and form labyrinth-like passages through which the lubricant must pass while being centrifuged. Openings c are provided in the intermediate bottom b for the passage of the lubricant to the upper compartment of the apparatus.

. apparatus is so suspended in the vessel contain- The `power vehicle, for example an automobile.

ing the lubricant. for example in the sump of a power vehicle, that its lower part is immersed in the lubricating liquid. 'I'he lubricant to be cleaned enters the centrifuge through the bottom inlet'a2 and is first thrown into the outer space adjacent the side wall a of the casing by the rotating blade wheel d. The magnetic ribs a1 project into this space and divide it into a number of compartments. The specifically heavier mechanical impurities which have been thrown outwards sink down in these compartments and, in so far as they are of metallic origin and magnetisable, are attracted by the magnetic ribs and retained on them. The lubricating liquid passes through the labyrinth-like passages formed by the ribs h on the intermediate bottom b and through the openings c into the upper compartment of the apparatus. A similar process is repeated in this compartment by the action of the centrifugal wheel d1 and the lubricating liquid, after having been freed from mechanical impurities and above all from the magnetisable particles therein, passes through the openings a4 in the cover a3 of the apparatus again into the oil sump or, as illustrated, to the oil pump y, al which supplies it to the different places to be lubricated.

In vFigure 3, the reference i denotes a rotary drum to the sides of which inwardly directed blades k are fixed and of which the bottom is fixed on a driving shaft l. This shaft can be one of the shafts of the oil pump which is extended so far downwardly that the bottom of the drum i can b e fixed thereto. The bottom of the drum is provided with openings m for the entry of the lubricating liquid. A sleeve n having radial ribs n1 is placed around the shaft l from the top.

The top rf the sleeve may be fixed to the fixed bottom ot the oil pump, which is assumed to be arranged above the centrifuge, or it may be xed to the shaft and rotate together with the shaft and the drum. In the first-mentioned case sufficient clearance is left between the outer ends of the ribs nl of the stationary sleeve n and the ends ofthe blades k to enable the centrifugal drum carried by the shaft l to rotate with the shaft. In the form of construction with a rotating centrifugal drum both its outer wall as well as its blades may be provided with magnetic fields of force for retaining the magnetisable particles of impurities.

In Figure'4 which represents a section through a single stage centrifuge, the reference o denotes the casing of the oil pump y, g1 from which the casing p of the centrifuge is suspended. The reference 1' denotes a part of the oil sump of a The bottom p1 of the centrifuge supports a partition s having an inwardly bent cover s1 which forms an intermediate bottom. The partition s encloses an annular space which is open to the inside and in which radial ribs t are arranged. These and the partition s are electrically energised and produce magnetic fields of force. Between the casing p of the centrifuge and the partition s there is a free space in' which the velocity of the centrifuged liquid becomes reduced. 'Ihe reference u denotes one of the shafts of the oil pump for circulating the lubricant, which, as illustrated, may be a gear pump.. The shaft u is extended downwardly and carries the centrifugal wheel v having blades v1 disposed at the same level as the ribs t on the partition s. The centrifugal wheel v is inset in a circular aperture in the said casing to its periphery of greater cross seccover s1 of the partition s and has an upwardly projecting edge v2 which extends partly overA s1 and holes y in the cover of the centrifuge are provided for the passage of the liquid to be 4cleaned hich takes the path indicated by the arrows inFigure 4 while the centrifuge is being rotated.

All mechanical impurities are thrown outwardly by centrifugal force, y against the partition s and sink downwardly at this place. The magnetisable particles of impurities are attractedand retained by the magnetic fields Vof force'of the partition s and its ribs t. The velocity of those particles of impurities which are not magnetically retained and separated and which pass through the holes s2 inthe intermediate cover S1 is reduced in the space above the cover and the particles sink into the annular space between the casing v and the partition s and are deposited at the bottom of this space.

'I'he inlet openings to the centrifuge for the passage of lubricating liquidto be mechanically puried and the passages and outlet openings for the cleaned or purified liquid are provided in the vicinity of the axis of the centrifuge because the centrifugal force is least there. Owing to the contaminated lubricating liquid being thrown on bycentrifugal force into magnetic elds of force, all magnetisable mechanical impurities, especially metallic impurities, are separated without any danger of the passages for the lubricating liquid being blocked. 'I'he lubricating liquid leaves the dition in which it is freed from all mechanical i impurities, and fresh impurities by which it becomes contaminated in continuous or circulating lubricating systems are always removed at once.

f Since the mechanical4 impurities are thrown outwardly toward the periphery, the opening for the passage and escapeof the purified liquid are preferably provided, as previously mentioned, in the central part of the centrifuge. If the velocity of the -liquid is'to be given a small component in the direction of outow, centrifugal i I central part of said casing, inwardly directed ribs on-said casing defining settlement chamberstherein, said casing being adapted to be influenced by magnetic fields of force acting thereon,

two or more-superimposed centrifugal wheels ln said casing deflning passages'from the inlet of ifying apparatus in a con-.

tional area 'at the periphery than at the center, intermediate partitions between said wheels and a passage in the central part of said partitions.

2. Apparatus for removing impurities from liquids, comprising a centrifuge having a vdrumlike casing, inlets and outlets for the liquid in the central part of said casing, a lower inner casing between which and said drumlike casing an annular space is formed, said inner casing being provided withinwardly directed ribs and magnetic elds of force and with a fixed cover having acircular aperture, a centrifugal wheel inlet in said aperture adjacent said ribs, said centrifugal wheel overlapping the edges of said circular aperture in said inner casing, a fixed central tubular member depending from the cover of said drumlike casing, the free endV of said. .tubular member extending downwardly to form an annular slot between its edge and the edge of said centrifugal wheel, and outlet openings in the cover of said drumlike casing inside said tubular member.

3. A device for removing impurities from liquid lubricants adapted to be connected to the oil pump of an internal combustion engine comprising a. drumlike casing, a driving shaft extending from said oil pump into said casing, a centrifugal wheel in the casing driven by said shaft,

. oil pump of an internal combustion engine comprising a drumlike casing, centrally located inlets and -outlets in opposite ends of the casing, a driving shaft extending into the interior of said casing from the oil pump, two or more centrifugal wheels mounted on said driving shaft, blades on 'said centrifugal wheels for forcing liquid toward the -periphery thereof, an arcuately ri bed plate mounted on said casing between the c ntrifugal wheels, the ribs on said plate being in staggered relationship and forming channels on the plate, inwardly extending ribs on the casing defining settlement chambers' therein, said settlement chambers being adapted to be influenced by magnetic nelds of force.

5. An apparatus for removing impurities from y liquid lubricants comprising a drumlike casing,

` thereof inwardly extending ribs on the casing dening settlement .chambers therein, saidsettlement chambers being adapted to be influenced by magnetic elds of force.

MAX ARMBRUSTER. 

